Portable concrete mixing foamating and dispensing machine



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PORTABLE CONCRETE MIXING, FOAMATING AND DISPENSING MACHINE 6Sheets-Sheet 3 Filed July 15. 1959 y INVENTORS.

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PORTABLE CONCRETE MIXING, FOAMATING AND DISPENSING MACHINE Filed Julyl5, 1959 6 Sheets-Sheet 4 IN'VENToRs. ff/654 fr Anf/Ps` BY NIF/IY d./l/L ff I Jan. 16, 1962 c. AYERs x-:rAL 3,017,164

PORTABLE CONCRETE MIXING, EOAMATINC AND DISPENSINC MACHINE Filed July15, 1959 e sheets-sheet s Jan. 16, 1962 l c. AYERs TAL PORTABLE CONCRETEMIXING, FOAMATING AND DISPENSING MACHINE Filed July l5, 59

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INVENTORs.

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@site States Patent 3,017,164 PRTAELE CONCRETE MIXING. FAMTING ANDBISPENSING MACHINE Chesley Ayers, Dearborn, and Wray I. Bailey, Detroit,

Mich., assignors to Acme Rotating and Sheet Metal Company, Detroit,Mich.. a corporation of Michigan Filed July 15, 195i?, Ser.. No. 827,2542 Claims. (Cl. 259-151) This invention relates to foam concrete and, inparticular, to machines for the preparation and application of foamconcrete.

Foam concrete is a cellular concrete, the cells of which contain airmechanically entrained in the concrete mix. This is done either bywhipping air into the concrete mix by the shearing action of the bladesof a high speed mixing machine or by adding to the concrete mix atemporarily-stable air-containing foam produced by combining afoam-producing compound with water in the presence of compressed air,The density of the resulting product can be varied from about l2() lbs.per cubic foot for neat concrete to about 20 lbs. per cubic foot forfoam concrete.

Hitherto, such foam concrete has been made by one of the methods justdescribed and then separately applied by hand to the surface on which itis to rest or impelled pneumatically from the container to the point ofdelivery. When the foam concrete has been produced in large volume, ithas ordinarily been mixed at a central mixing star tion from which it isdistributed to the point of application. This prior procedure, however,has resulted in a loss of time between the start of mixing the batch andthe completion of application of the foamated mix, with consequentlyhigh labor and operating costs, as well as involving costly breakdownswhere there is a failure of any element in the chain of production anddistribution. The prior procedure, moreover, has not been continuous butintermittent, and has entailed halts and stoppages in the operationsboth of production, distribution and application of the foam concrete.

The present invention provides a portable machine wherein the foamatingliquid is mixed with water while the concrete batch or mix is also beingprepared, the foam being generated and applied to the concrete mix inthe same machine and the foamated concrete mix then dumped by gravityinto a hopper in the machine from which it is pumped through a hose to anozzle at the point of utilization. In this manner, the foam concretemix can be applied rapidly. inexpensivelv and continuously since onebatch of foam-producing liquid is being generated into foam and thenapplied to the concrete mix while another batch thereof is beingprepared in the machine.

Accordingly, one object of the invention is to provide a portablefoam-concrete producing and dispensing machine which mixes thefoam-producing liquid with water while the concrete mix is beingprepared in another part of the machine, generates temporarily stablefoam in the presence of compressed air, applies the foam to the concretemix, which, after further mixing, is deposited by gravity in a hopperfrom which it is pumped in a fluid condition through a hose to the pointo-f utilization where it is deposited by means rof a suitable nozzle.

Another object is to provide a portable foam-concrete producing anddispensing machine of the foregoing character wherein means is providedfor compounding one batch of foam-producing liquid with water while ana-lready compounded batch is being impelled through a foam generator bymeans of compressed air into a concrete mix and there subjected to themixing action of paddle blades.

Another object is to provide a portable foam-concrete producing anddispensing machine of the foregoing character wherein means isadditionally provided for running water under pressure through theportions of the machine carrying or containing the foam and the concretemix after the use of the machine has ceased, in order to clean out thefoam generator and flush out the concrete before it has an opportunityto harden, thus eliminating the difficult and costly manual operation ofremoving hardened foam concrete from the machine.

Other objects and advantages of the invention will become apparentduring the course of the following description of the accompanyingdrawings, wherein:

FIGURE l is a side elevation of a portable foam concrete producing anddispensing machine, according to one form of the invention;

FIGURE 2 is a top plan view of the machine shown in FIGURE l;

FIGURE 3 is a longitudinal section through the central portion of themachine of FIGURE 1 wherein the concrete mix batch is mixed, foamatedand dispensed, taken along the line 3--3 in FIGURE 4;

FIGURE 4 is a cross-section, looking forward, taken along the line 4-4in FIGURE 3;

FIGURE 5 is a horizontal section, taken along the zigzag line 5 5 inFIGURE 4, showing details of the mixing paddle drive and mixing paddles;and

FIGURE 6 is a diagramma-tic view. roughly in rear elevation, of themachine of FIGURES l to 4 inclusive, showing the foam liquid compoundingand generating circuit.

Referring to the drawings in detail, FIGURES l to 3 inclusive show aportable foam-concrete producing and dispensing machine, generallydesignated 10, according to one form of the invention as consistinggenerally of a trailer wheeled chassis 12 upon which is mounted apower-driven concrete mixing `and foamating unit 14 mounted in thecentral portion of the trailer 12, and a foam liquid mixing andgenerating unit 16 mounted on the rearward end of the trailer 12.

The trailer I2 is a heavy commercial type of trailer having a frame 18on which front and rear axles 20 and 22 are mounted by means of suitablesprings 24 and carry the usual rubber-tired wheels 26. The trailer 12 atits forward end is provided with a conventional draft bar 28 by which itis attached to and towed by a conventional tractor or truck (not shown).Mounted on the frame 18 and extending upwardly therefrom areapproximately triangular struts 30 (FIGURE 4) which in turn supportlongitudinal running boards or walkways 32 of steel or other suitablematerial upon which the operator can stand or move about, as requiredduring operation of the machine. On one side of the machine 10, therunning board 32 carries an elongated raised platform 34 of invertedbox-shaped construction by means of which the operator can mount to ahigher level in order to perform certain operations upon the central ormixing and foamating unit 14, as described below. A portable anddetachable ladder 36 enables the operator to ascend to the level of therunning board 32 on the left hand side of the machine 10. y

Mounted forward of the trailer 12 and interconnecting the longitudinalwalkways 32 is a cross platform 38 upon which are mounted a power unit,generally designated 4i), and an air compressor unit, generallydesignated 42. The power unit 4t) includes an internal combustion engine44 having a crankshaft or output shaft 46 (FIGURE 3). Keyed or otherwisedrivingly secured to the crankshaft 46 is a sprocket 48 which drives asprocket chain 50, the latter in turn driving a large sprocket 52 keyedor otherwise drivingly secured to a countershaft 54. Also keyed orotherwise drivingly secured to the countershaft Patented Jen. 16, 196254, which is rotatably supported upon bearings 56 and S beneath thewalkways 32 is a. sprocket 60 which meshes with a sprocketchain 62driving a large sprocket 64 keyed or otherwise drivingly secured to arotary paddle shaft 66. A guard housing 68 covers the sprockets andsprocket chains just mentioned, for safety purposes.

The paddle shaft 66 is rotatably supported in bearings 70 and 72 at theopposite ends of a concrete mixing cylinder or casing, generallydesignated 74, and carries the hubs of two pairs of oppositely-extendingarms 76 pinned or otherwise drivingly secured to the shaft 66. Extendingbetween each pair of arms 76 are mixing slats or blades 78 extending ina generally longitudinally direction. The arms 76 of each pair aredisposed in slightly different positions circumferentially of the shaft66 (FIG- URE 5) and are of channel cross-section, with the result thatthey form, with their slats or blades 78, a pair of oppositely-extendingpaddles, generally designated 80, the slats 7S of which are disposed ina skew position relatively to the shaft 66 so as to urge the concretebatch or mix toward the center of the mixing cylinder or housing 74while mixing is taking place. In this manner, the paddles 86 possess aroughly screw-like action (FIG- URES 4 and 5).

The mixing cylinder 74 on its upper side toward the platform 34 isprovided with an elongated approximately rectangular hatchway or inlet82 having an inlet passageway 84 closed by a grating 86 composed oflongitudinal bars 88 and arcuate cross bars 11 welded to one another andcarrying roughly triangular bag-splitting bars 92. The grating 86 ispivoted to pivot bolts or pins 94 mounted on the end members 96 of theinlet 82. The grating 86 is of coarse formation so that bags of cementcan be thrown directly down upon the bag-splitting bars 92 and brokenapart, the cement passing through the grating 86 but the paper or othermaterial of which the broken bag is composed remaining behind, asexplained in connection with the operation of the invention.

Also mounted on the upper side of the mixing cylinder 74 (FIGURES 3 and4) is a water inlet connection 98 for a water supply pipe 161) and afoam inlet connection 102 to which is connected the forward end of afoam-generator, generally designated 164, forming the terminal portionof the foam liquid compounding and foam generating unit 16 described inmore detail below.

The concrete mixing cylinder 74 is supported by a supporting structure,generally designated 106, extending upwardly from the chassis 18(FIGURES 3 and 4) and holding the cylinder 74 in a fixed position. Thebottom of the cylinder 74 is provided with an outlet or dischargeopening 108 extending longitudinally thereof and of rectangular outline.The discharge opening 108 is closed by an overlapping bottom door ordischarge gate 11) of arcuate cross-section swingably supported on threearms 112, the opposite ends of which are keyed or pinned to a pivotshaft 114. The pivot shaft 114 is supported in bearings 116 secured tothe opposite end plates 118 of the mixing cylinder 74. The forward endof the shaft 114 (FIGURE 3) projects from its respective bearing 116 andcarries an operating arm 119 pinned or otherwise drivingly securedthereto.

The arm 119 is drilled to pivotally receive the bent lower end 120 of anoperating link or connecting rod 122, the upper end of which passesthrough a suitably drilled block 124 which in turn is rockably mountedat 125 upon a manual dumping lever 126. The upper end portionV of therod 122 is threaded to receive an adjustable stop nut 128 by which thepoint of contact of the block 124 with the rod 122 can be varied. Theupper end of the rod 122. is also threaded to receive a spring abutmentnut 136, the abutment washer 132 of which engages one end of acompression spring 134, the other end of which engages the rocking block124 as an abutment. The manual dumping lever 126 is pivotally mountedupon the pivot shaft or pin 136 (FIGURE 4) which in turn is supported inthe end plate 118 of the concrete mixing cylinder 74. The arm 119 ismounted in such a position on the gate shaft 114 and the manual dumpinglever 128 and connecting rod or link 122 so constructed and arrangedthat the rod 122 swings across dead center of the pivot shaft 114 whenthe lever 126 is between the gate-closing and gate-opening positions, asshown in FIGURE 4 by the solid line and dotted line positions thereof,thus providing a toggle action for these parts.

The discharge gate 116 and opening 168 (FIGURES 3 and 4) are disposeddirectly above and open into a receiving bin or concrete dispensingcasing or hopper, generally designated 138, of open-topped box-likeconstruction with forward and rearward end walls 140 and 142respectively interconnected by side walls 144 and 146, all of which areinterconnected by a shallow funnelshaped bottom wall 148 ofapproximately pyramidal form terminating in an outlet plate 151i with anoutlet opening 152. Connected to the outlet plate 158 is the intakeconduit 154 of a conventional liquid concrete pump 156 adapted toreceive the foamated concrete mix from the hopper 138 by the combinedaction of gravty and its own suction, and discharge the foamatedconcrete mix through the outlet or dischrage conduit 158. The oppositeend of the pump 156 is provided with a tubular support 160 coaxial withthe outlet conduit 158 and like the latter is supported in brackets 162secured to and depending from the chassis 18 (FIGURES 3 and 4). Thetubular support has an access opening 164 to enable the operator toreach the packing gland 166 around the pump drive shaft 168.

Mounted coaxial with the engine shaft 46 on the opposite sides of thesprocket 48 is an extension shaft 170 (FIGURE 3) mounted in bearings171, and beyond it is a separate coaxial shaft 172 mounted in a bearing173. A clutch 178 with a shift collar 175 and yoked shift lever 176connects the extension shaft 176 to the shaft 172. The shift lever 176,pivotally mounted at 177 (FIGURE 5) enables the driving connectiontherebetween to be connected or disconnected as is necessary to operatethe pump 156 or not. Keyed or otherwise drivingly secured to the shaft172 is a sprocket 180 driving a sprocket chain 182 which in turn drivesa sprocket 184 drivingly connected to the outer end of the pump driveshaft 168. The pump 156 itself discharges into the discharge conduit 158and this in turn discharges into a transverse hose connection pipe 186(FIGURE 5) connected thereto through an elbow fitting 188. A flexibleuid concrete delivery hose 190 is coupled at 192 to the hose connectionpipe 186 and at its outer end carries a concrete application nozzle 194(FIGURES l and 2).

Also mounted on the cross platform 38 beside the power unit 40 is theair compressor unit 42 (FIGURES 1 and 2) which consists of a casing 196containing an auxiliary internal combustion engine (not shown) and aircompressor driven thereby (also not shown), together with three`compressed air storage tanks or bottles 198, each having an outletcontrol valve 199. A compressed air supply pipe 200 extends from thecompressed air tanks 198 forwardly to a compressed air service takeoffcoupling 262 preceded by a shutoff valve 204 (FIGURE 2) and rearwardlyto the upper part of the foam liquid mixing and foam generating unit 16on the rearward end of the trailer 12, shown in the upper centralportion of FIGURE 6.

Connected to the rearward end of the compressed air supply line 206(FIGURE 6) is a conventional air cleaner 266, continuing to a T-junetionwith a pair of compressed air lines 208 `and 210 containing shutoffvalves 2112 and 214 and pressure gauges 216 and 218 before reachingT-connections with two lines 221B and 222 containing lower controlvalves 224 and 226 between which a single line 228 runs through an airmeter 230 of the type known commercially as a rotameter to a rearwardend connecting fitting 231 of the foam generator 104. The opposite endsof the lines 22) and 222 run to connections 232 and 234 in the upperends of foam liquid mixing tanks 236 and 238 respectively. Theconnections 232 and 234 contain pressure relief valves 240 and 242 -andalso are connected to the upper ends of liquid lines 244 and 246containing upper sight gauges 248 and 250 as well as lower sight gauges252 and 254. The lower ends of the liquid lines 244 and 246 extend toconnections 256 and 258 at the lower ends of the mixing tanks 236 and238 respectively, and terminate in drain valves 257 and 259respectively. Each sight gauge 248, 250, 252 and 254 has upper and lowervalves 268 and 262 which may be opened or closed in order to` permit orterminate the ow of liquid from the tank 236 or 238 into the particularsight gauge.

Water is supplied to the foam-liquid mixing and generating unit 16through a connection 264 (FIGURE 2) to which a hose 266 is coupled, theopposite end of the hose 266 being coupled to an ordinary re hydrant268, the valve of which is controlled by the usual hand lever or wrench270 on the squared valve shaft 272. The connection or coupling 264 islocated on the outer or rearward end of a pipe 274 leading to oppositebranch pipes 276 and 278 which in turn lead through valves 280 and 282and pipes 284 and 286 to connections 288 and 290 with the tanks 236 and238 near the bottoms thereof. The pipes 284 and 286 contain eductors 292and 294 respectively operating on the ejector principle to create asuction in the vertical pipes 296 and 298 containing the check valves380 and 382 and the shutoff valves 304 and 386 when water flows throughthe p-ipes 284 and 286 into the mixing tanks 236 and 238 respectively.Receiving funnels 297 and 299 for concentrated foamforming liquid aremounted on the upper ends of the vertical pipes 296 and 298.

The left-hand branch water pipe 276 (FIGURE 6) also leads to a Watermeter 388 mounted on the stand 310 which in turn rests upon the walkway32. The water meter 388 is preceded by a check valve 312 and shutoffvalves 314 and 315 (FIGURE l) located in the upper portion of the pipe276. From the opposite side of the water meter 308 the water dischargepipe 100 runs to the connection 98 on the top of the mixing cylinder 74,whereby water is supplied to the latter for mixing with the cement. Theright-hand branch pipe 278, in addition to connection with the pipe 286leading to the mixing tank 238, also extends forwardly through a Valve316 (FIGURES 5 and 6) and hose connection coupling 318 located in theapproximate midportion of the trailer 12 (FIGURES 2 and 3). Connectionto the coupling 318 is made either by the concrete delivery hose 190after use, for flushing it out, or by a ushing hose 320 which is used toush out other portions of the apparatus after use.

A ilushing pipe 322 for Hushing out the foam generator 104 after use isconnected to the water pipe 278 near vits junction with the water pipes274 and 276 and runs upward past a T iitting 324 with a shutoi valve 326and a hose coupling 328 for the connection of another ushing hose (notshown). The pipe 322 runs through a shutoff valve 338 to the rearwardend of the foam generator 104. The foam generator 104 is of elongatedconical form containing plastic beads which assist in bringing about thefoam-producing action of the foam generator 184. Mixed or dilutedfoamating liquid is delivered from either of the mixing tanks 236 or 238thro-ugh vertical feed pipes 332 and 334, through check valves 336 and338 and upper control valves 340 Iand 342 to a common junction with afoamating liquid supply line 344 also leading through a foamating liquidmeter 346 commercially known as a rotameter to the rearward end tting231 of the foam generator 184. The lower control valves 224 and 226 andthe upper control valves 340 and 342 are interconnected for simultaneousactuation by handles 348 and 350 respectively, so that swinging of theAhandle 348 simultaneously opens or closes the air valve 224 and mixedfoamating liquid valve 340, whereas swinging of the handle 350 similarlyand simultaneously opens or closes the corresponding valves 226 and 342.Each mixing tank 236 or 238 near its upper end is provided with apressure gauge 352 or 354. The compressed air pipes 220 and 222 areprovided with branch pipes 356 and 358 containing shutoff valves 368 and362 respectively.

in the operation of the invention, let it be assumed that the power unit48 and the air compressor unit 42 have both been started in operation sothat the former rotates the paddles in the concrete mixing cylinder 74and the latter supplies compressed air to the tanks or bottles 198, theoutlet valves 199 being closed, for the moment, in order to accumulatecompressed air iu the tanks 198. Let it also be assumed that the shiftlever 176 of the clutch 178 has been shifted in a direction opening theclutch 178 so as to disconnect the driving connection between the shafts178 and 172 and consequently to render the pump 156 inoperative for thetime being. Let it be further assumed that the machine 18 has been movedto a location where the foam concrete is to be depo-sited near where aiire hydrant 268 is conveniently located and that a hose 266 has beenrun from the re hydrant to the water connection 264 of the machine 10.Let it n-ally be assumed that the gate 11) at the bottom of theconcrete-mixing cylinder 74 has been closed by suitable manipulation ofthe hand lever 126 and that a supply of Portland cement and concentratedfoamproducing liquid is on hand.

To prepare the foam-liquid mixing and generating unit 16 for operation,the operator lls the tanks`236 and 238 to a suitable level as indicatedin the sight glasses 248 and 258 (FIGURE 6) by opening the valves 288and 282, having previously deposited in the receiving funnels 297 and299 a suitable quantity ofthe concentrated foam-producing liquid. Thevalves 384 and 386 below the receiving funnels 297 and 299 are openedwhen the water supply valves 280 and 282 are opened, so that as thewater ows from the re hydrant 268 through the hose 266 and pipes 274,276, 278, 284 and 286 into the mixing tanks 236 and 238 respectively,the eductors 292 and 294 by this water flow are caused to exert suctionin the vertical pipes 296 and 298, drawing the concentratedfoamproducing liquid in the receiving tunnels 297 and 299 through thevalves 384 and 386 and the check valves 388 and 382 and the eductors 290and 294 into the tanks 236 and 238, thereby causing the tanks 236 and238 to be lled with a diluted water solution of the concentratedfoanvproducing liquid previously deposited in the receiving tunnels 297and 299. When both tanks 236 an-d 238 have thus become lled to theproper levels with the foam-producing solution, as indicated in thesight glasses 248 and 258, the Water valves 280 and 282 are closed,together with the foam liquid control valves 384 and 306.

Compressed air is now admitted to the pipe 288 (FIG- URES l and 2) byopening one of the compressed air bottle valves 199, and permitted toenter the spaces above the liquid levels in the mixing tanks 236 and 238(FIG- URE 6) by opening the air control valves 212 and 214, therebypermitting compressed air to ow through the pipes 208 and 218 into thepipes 228 and 222 and thence through the tank connections 232 and 234into the upper ends of the tanks 236 and 238. Meanwhile, the controlvalve handles 348 and 358 have been kept in their closed positions.

Having lled the foam-liquid mixing tanks 236 and 238 with foam-producingliquid solution, in the manner just described, the operator now preparesthe concrete batch by dumping the necessary ingredients through thegrating 86 and opening 84 into the concrete-mixing cylinder 74. The bars88 and 90 of the grating 86 break up chunks of material, and enablepaper bags of Portland cement to be thrown downward onto the members 92.The paper bags rupture, releasing the cement to pass through theinterstices of the grating S6, whereas the bags themselves remain behindwithout entering the mixing cylinder 74. The operator, having depositedthe cement and other ingredients for the concrete batch or mix in theconcrete mixing cylinder 74, admits a metered amount of water thereto byopening the valve 314 (FIGURE 1), causing Water to flow through thewater meter 308 and pipe 100 into the top of the concrete mixingcylinder 74 and thence into the batch. The rotation of the paddles 80 bytheir connection through the sprockets 64, 60, 52 and 48 and sprocketchains 62 and 50 (FIGURE 3) to the internal combustion engine 44 of thepower unit 40 mixes the ingredients of the concrete batch with thewater.

To foamate the concrete batch in the mixing cylinder 74, the operatornow swings one of the handles 348 and 350 (FIGURE 6) to the rightopening one pair of the valves, say the valves 340 and 224 while leavingclosed the other pair 342 and 226. Impelled by the pressure of thecompressed air in the top of the foam liquid mixing cylinder 236, themixed foam liquid solution therein is forced upward through the pipe332, check valve 336, upper valve 340, liquid rotameter 346 and pipe 344and connection fitting 231 into the foam generator 104. Simultaneouslytherewith, compressed air ows from the compressed air supply pipe 200(FIGURE 6) through the now-open compressed air valve 212 (the similarvalve 214 being closed), through the pipes 208 and 220 and lower controlvalve 224, thence through the pipe 228 and air rotameter 230 through theconnection tting 231 into the foam generator 214. The interaction of thecompressed air upon the foam liquid solution passing between the plasticbeads in the horn-shaped foam generator 104 causes a temporarily stablefoam to be generated and passed through the connection 102 into theconcrete mixing cylinder 74 where it becomes thoroughly mixed with theconcrete batch by the action of the rotating paddles 80.

When the concrete batch in the mixing cylinder 74 has been thoroughlyfoamated, the operator shifts the dumping control lever 126 from itsupper position (FIGURE 4) to its lower position, thereby swinging thelink or rod 122 across dead center of the pivot shaft 114 while causingthe arm 119 to rotate the pivot shaft 114 in a counterclockwisedirection so as to swing the gate or door 110 downwardly to open thedischarge outlet 108 and permit the foamated concrete batch to drop intothe hopper 133 beneath it. The batch is in a fluid condition, due to thepresence of the water and foam in the batch, hence the operator nowshifts the clutch lever 176 (FIGURES 2 and 5) to close the clutch 178and drive the pump 156i. As a result, the fluid foamated concrete batchin the hopper 138 is drawn by gravity and the suction of the pump 156into the latter and thence impelled through the outlet conduit 158 andpipe 186 (FIGURE 2) through the discharge hose 190 and nozzle 194 ontothe wall, roof, piping or other surface to be coated with foam concrete.

Meanwhile, after mixing tank 236 has become emptied of its contents, asindicated by the level of the liquid shown in its lower sight glass 252,the operator shifts the valve handles 348 and 350 (FIGURE 6) so as tosimultaneously close the upper and lower valves 340 and 224 andsimultaneously open the corresponding upper and lower valves 342 and226. This action shifts the supplying of foamating liquid solution fromthe empty tank 236 to the iilled tank 233 and causes the contents of thelatter to be discharged into the foam generator 104. The operator,having closed the dumping gate 110 in the bottom of the concrete mixingcylinder 74, places a new batch of concrete ingredients therein,including dry materials through the grate 86 and water through the pipe100, then opens the valves 342 and 226 simultaneously by swinging thehandle 350 into its open position, thereby causing foam-producing liquidto ow through the pipes 334 and 344 into the foam generator 104 whilecompressed air flows through the pipes 222 and 228 into the foamgenerator 104, the resulting foam iiowing through the connection 102into the top of the concrete mixing cylinder 74 while the paddles 80convert these ingredients into uid toamated concrete.

In the meantime, the operator refills the emptied mixing tank 236 in themanner previously described, readying it for the next batch, and byshifting from one tank 236 to the other tank 23S and back again, theprocess is rendered substantially continuous, each foarnated batch ofconcrete being dumped into the hopper 138 below the concrete mixingcylinder 74 as soon as it has become fully processed. Thus, a continuousilow of iluid foamated concrete is enabled to be supplied through thehose and nozzle 194 to the work.

At the end of the day, or when operations have been concluded, theconcrete mixing tank 74 and hopper 138 are emptied, and the systemflushed out with water by means of the pipes described below. The foamgenerator 104 is hushed out by opening the valve 330 (FIGURE 6), therebypermitting water under pressure to iiow through the flushing pipe 322and foam generator 104 into the concrete mixing cylinder 74. The hopper138 and other parts of the machine may be iiushed out or washed off bymeans of the flushing hose 320 (FIGURE 2). The concrete delivery hose190 and its connected pipes 158 and 186 are hushed out by operating thepump 156 to pump water from the hopper 138 instead of fluid concrete.

When the liquid-mixing tanks 236 and 238 are empty, they too can beflushed out by passing water alone through the pipes 234 and 294, withthe valves 280 and 282 opened, while the drain valves 257 and 259 at thebottom are opened to permit the ilushing water to run out. In thismanner, the cylinder 74, hopper 138 and foam generator 104 are flushedout immediately after the conclusion of operations so as to prevent anyconcrete or foam remaining in the machine and thus prevent theaccumulation of hardened concrete therein. This hardened concrete, evenfoam concrete, is otherwise diiiicult and expensive to remove after ithas hardened.

What we claim is:

l. A portable concrete mixing, foarnating and dispensing machinecomprising a wheeled chassis, a concrete mixing casing mounted on saidchassis intermediate the opposite ends thereof and having an inletopening in the upper portion thereof and an outlet opening in the lowerportion thereof, a concrete mixing device movably mounted in saidcasing, a closure member movably mounted adjacent said outlet opening, aconcrete dispensing casing mounted below said mixing casing incommunication with said outlet opening, a fluid concrete pump disposedadjacent said dispensing casing and having an intake passagewaycommunicating therewith and also having a discharge passageway, a fluidconcrete dispensing conduit connected to said discharge passageway,means for generating and delivering concrete foamating material to saidmixing casing including foamating material mixing apparatus mounted onone end of said chassis and a foamating material generator mountedadjacent the upper part of said concrete mixing casing and connected tosaid foamating material mixing apparatus, and a prime mover drivinglyconnected to said mixing device and pump, said foamating material mixingapparatus including a pair of foam solution mixing tanks mounted at saidone end of said chassis and having foam liquid and water inletsconnected thereto, said foamating material generator having an outletconnected to said mixing casing and also having an inlet, an aircompressor, air piping including tank air valves for selectivelyconnecting said air compressor to said tanks, said air piping alsoincluding foamating air valves for connecting said air compressor tosaid foam generator inlet, and a liquid piping system connecting saidtanks to said foam generator inlet and including liquid valves foralternatively connecting one only of said tanks to said foam generatorwhile disconnecting the other tank from said foam generator.

2. A portable concrete mixing, foamating and dispensing machine,according to claim 1, wherein said foamating air valves and liquidvalves are disposed in pairs and have operating handles operativelyinterconnecting each pair for simultaneous actuation thereof, eachinterconnected pair of valves including a foamating air valve and aliquid valve.

1,281,674 Seweryn Oct. 15, 1918 10 Dimm July 1, 1924 Jaeger Apr. 16,1929 Shields Nov. 20, 1934 Friedrich June 27, 1939 Urquhart et al. Apr.23, 1940 Wehner Jan. 31, 1950 Bower Apr. 10, 1951 Baumann May 15, 1951McCoy Jan. 4, 1955 Boerner et a1 July 16, 1957 Whitehead et al. Oct. 15,1957 Selden Dec. 1, 1959

